(2u+5)(3+u)=0

Solution for (2u+5)(3+u)=0 equation:

(2u+5)(3+u)=0

We add all the numbers together, and all the variables

(2u+5)(u+3)=0

We multiply parentheses ..

(+2u^2+6u+5u+15)=0

We get rid of parentheses

2u^2+6u+5u+15=0

We add all the numbers together, and all the variables

2u^2+11u+15=0

a = 2; b = 11; c = +15;
Δ = b2-4ac
Δ = 112-4·2·15
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(11)-1}{2*2}=\frac{-12}{4}
=-3
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(11)+1}{2*2}=\frac{-10}{4}
=-2+1/2
$